If Watson and Siri were to 'get-it-on', OMG, we will have a true (spoken) natural language answer engine that speaks back. We might be a year away from this because there are things to be worked out. For instance, Watson was predicated on a created database, not the internet. And Siri is currently in Beta, albeit in a very good state, but still needs to be tweaked.

Research is not stagnate, and I am sure significant progress has been made that the average person is not yet entitled to. IMO, this is significant enough to merit caution on Google's multiple. (Even when backing out Google's cash, it is still pricer than Apple.)

Keep in mind, I do not think Google is stupid either. They know this, and have been transitioning their search to be more of an answer engine. This is also another reason why they purchased Motorola. The only way to make money from an answer engine, especially one that speaks the answer back to you in a mobile format, is to sell the hardware, software or be involved in the answer. Google will look more and more like Apple over the next few years.

Depending how quickly the 'answer engine' transition takes place, and if Google is lacking in their transition, is how severe Google's multiple will contract. The worst case scenario could be the Microsoft Effect. Where MSFT lost device market share of 95% to some 40% in a span of 3-4years, and despite its growing EPS base, its trailing multiple is near 10.